1. Technical Field
The present invention generally relates to an apparatus and method for testing an xDSL transceiver unit-central office to measure performance of a transceiver unit by automatically converting many output ports by connecting a multiplexer to the xDSL transceiver unit.
2. Related Art
An xDSL or “digital subscriber line” is a technology involving digitally speeding up a high speed subscriber network prior to perfect optical cabling by using an existing subscriber line. It uses a wideband network as a backbone network, and uses an existing coaxial line as the subscriber network occupying the most important investment position among communication networks.
Generally, a basic model for an asymmetric DSL (ADSL) network construction requires network element devices such as a subscriber terminal unit, a digital subscriber line access multiplexer (DSLAM), and a network access server (NAS).
That is, an ADSL network basically includes an ADSL terminal unit-remote (ATU-R), a subscriber ADSL interface, an ADSL terminal unit-center (ATU-C), and a central office ADSL interface. The ATU-R and the ATU-C are connected to a twisted pair cable used for existing plain old telephone service (POTS) through a subscriber splitter and a central office splitter, respectively.
In such an arrangement, the ADSL signal is demodulated as digital data through the ATU-R and processed in the subscriber computer, and digital data of the subscriber computer is modulated through the ATU-R, and then transmitted to a digital subscriber line access multiplexer (hereinafter, “DSLAM”).
The DSLAM performs traffic concentration and relays of tens of or hundreds of subscribers between the subscriber terminal unit and the network access server (hereinafter, “NAS”), having a network interface for communicating with the central office splitter, the ATU-C, and a local backbone network (for instance, ATM network).
Furthermore, the central office splitter separates the signals transmitted through the twisted pair cable into an ADSL signal and a telephone signal for POTS, transmits the telephone signal for POTS to a telephone network (for instance, PSTN), and transmits the ADSL signal to the local backbone network through the ATU-C and the network interface corresponding to the number of subscribers as central office ADSL interfaces.
The NAS performs traffic processing in accordance with subscriber access, authentication, and data transceiving, connects the DSLAM to the Internet, and communicates between the local backbone network and a router. In addition, many DSLAMs installed in a corresponding local area are connected to the NAS.
Measurement of state, transmission rate and performance on DSLAM apparatus is performed repeatedly by port.
In another words, first, a line simulator is installed between an ATU-C and customer-provided equipment or CPE (at this time, a user optionally selects ports to be measured among many ports, and manually connects them), and a tester is connected to the ATU-C, the line simulator, and the CPE.
After that, the tester is operated to change line states of the line simulator, and a test signal is generated by controlling the ATU-C or the CPE in order to obtain measured data in accordance with each line state. Then, measurement data are received in accordance with the generated test signal from the ATU-C or the CPE.
At this point, when completing a test for one port, a test is conducted in accordance with the same method as described above by manually converting wiring to a next port.
However, in the case described above, since the wire has to be manually converted in order to conduct a test for the next port after completing the test for a previous port, this process requires considerable time if there are a lot of subscriber ports to be tested and a lot of simulation lines.
Also, if there are many DSLAM apparatuses to be measured, tests for abnormality, transfer rate and performance of the DSLAM apparatuses take a great deal of time in proportion to the number of apparatuses.
Moreover, since the tests for abnormality, transfer rate and performance of the DSLAM apparatuses are performed manually, it is difficult to conduct the test at night in order to reduce the testing period.
Furthermore, when the tests for abnormality, transfer rate and performance of the DSLAM apparatuses are performed, the tests statistics are compiled subjectively. Since the tester of the DSLAM apparatus is provided to test equipment developed by the equipment developer himself or herself, it is difficult to apply the tester to other equipment developed by another developer.